1. Field of the Invention
The present invention relates to a flat panel display device, and more particularly to a method and apparatus for fabricating a flat panel display device that is adaptive for performing a patterning process without using a photo process.
2. Discussion of the Related Art
Recently as society has become more information-oriented, the display device has been emphasized in importance more than ever before as a visual information communication medium. A cathode ray tube or Braun tube display is currently the most popular display device used. However the CRT display is heavy and large.
As an alternative, various flat panel displays have been developed. Examples of flat panel displays include liquid crystal display LCD, field emission display FED, plasma display device PDP, electroluminescence device EL, etc. Most of these displays have been put to practical use and are presently on the market.
Among these, the liquid crystal display device is popular as the liquid crystal display device can satisfy a trend of electronic products being made light, thin, short and small. As the producability of the liquid crystal display device has been improving, it has been rapidly replacing the cathode ray tube in many applied fields.
Specially, an active matrix type liquid crystal display device, which drives a liquid crystal cell by use of a thin film transistor (hereinafter, referred to as “TFT”), has an excellent picture quality and low power consumption. Large-sized and high-resolution active matrix type liquid crystal display devices have rapidly been developed due to the establishment of mass production technology and the result of research and development.
The active matrix type liquid crystal display device, as shown in FIG. 1, has a color filter substrate 22 and a TFT array substrate 23 bonded with a liquid crystal layer 15 therebetween. The liquid crystal display device shown in FIG. 1 represents part of the whole effective screen.
The color filter substrate 22 includes a color filter 13 and a common electrode 14 formed on the rear surface of an upper glass substrate 12. A polarizer 11 is adhered onto the rear surface of the upper glass substrate 12. The color filter 13 has red R, green G and blue B color filter layers arranged to transmit a light of a specific wavelength range, thereby enabling a color display. A black matrix (not shown) is formed between adjacent color filters 13.
The TFT array substrate 23 includes data lines 19 and gate lines 18 formed to cross each other in the front surface of a lower glass substrate 16, and TFTs 20 formed at the crossing parts. A pixel electrode 21 is formed in a cell area between the data line 19 and the gate line 18 in the front surface of the lower glass substrate 16. The TFT switches a data transmission path between the data line 19 and the pixel electrode 21 in response to a scan signal from the gate line 18, thereby driving the pixel electrode 21. A polarizer 19 is adhered to the rear surface of the TFT array substrate 23.
The liquid crystal layer 15 controls the transmitted amount of the light which is incident through the TFT array substrate 23.
The polarizers 11, 17 adhered onto the color filter substrate 22 and the TFT substrate 23 transmit polarized light in one direction, and the polarized directions thereof perpendicularly cross each other when the liquid crystal 15 is in a 90° TN mode. An alignment film (not shown) is formed in each of liquid crystal facing surfaces of the color filter substrate 22 and the TFT array substrate 23.
A fabricating process of the active matrix type liquid crystal display device can be divided into a substrate cleaning process, a substrate patterning process, an alignment film forming/rubbing process, a substrate bonding/liquid crystal injecting process, a mounting process, an inspecting process, a repairing process, etc. The substrate cleaning process uses a cleaning solution to remove impurities that have contaminated the substrate surface of the liquid crystal display device. The substrate patterning process is divided into a patterning process of the color filter substrate and a patterning process of the TFT array substrate. The alignment film forming/rubbing process spreads an alignment film over each of the color filter substrate and the TFT array substrate and rubs the alignment film with a rubbing cloth, etc. The substrate bonding/liquid crystal injecting process bonds the color filter substrate and the TFT array substrate together by use of a sealant and injects a liquid crystal and a spacer through a liquid crystal injection hole and seals the injection hole. The mounting process connects a tape carrier package (hereinafter, referred to as “TCP”), on which an integrated circuit such as a gate drive IC, a data drive IC, etc is mounted, to a pad part on the substrate. The drive IC can be mounted directly on the substrate by a method such as a chip-on-glass (hereinafter, referred to as “COG”) method besides a tape automated bonding method using the foregoing TCP. The inspecting process includes electrical inspection and macrography which are conducted after forming the pixel electrode and the signal line such as the data line and the gate line on the TFT array substrate. The repairing process performs restoration on a substrate which is judged by the inspecting process to be possible to repair. A substrate which is judged to be impossible to repair is disposed as waste.
In the fabricating method of most of the flat panel display devices inclusive of the liquid crystal display device, a thin film material deposited on the substrate is patterned by a photolithography process. The photolithography process is a series of photo-process which generally includes photo-resist spreading, mask aligning, exposing, developing and cleaning. However, the photolithography process takes a relatively long time, a large amount of the photo-resist material and stripping solution are wasted, and uses expensive equipment such as exposure equipment.